If the opioid induced pharyngeal and esophageal dysfunction and reduction of the lower esophageal sphincter pressure is peripherally induced or mediated via peripheral opioid receptors, methylnaltrexone might reverse these effects and thereby reduce postoperative morbidity by reducing pulmonary complications. On the other hand, if the dysfunction is centrally induced and not mediated via peripheral opioid receptors there is no effect of methylnaltrexone.